Adjustable chair



ADJUSTABLE CHAI R Filed June 26, 1937 I N VEN TOR Z f/uns/cer BY Z ATTORNEY.

.55 wise direction as viewed in Fig. 1.

Patented Oct. 1, 1940 UNITED, STATES PATENT OFFICE 2 Claims.

This invention relates generally to the construction of chairs capable of raising and lowering adjustments. Such chairs are widely used in professional and semi-professional offices, in order to place a patient at a desired elevation.

It is an object of the invention to providea chair of the above character which will have a relatively large range of adjustment, but which at the same time can be lowered to a position con- IO venient for children or patients of short stature.

Another object of the invention is to provide a simple type of mechanism for the raising and lowering of chairs, which will oifer a wide range of vertical adjustment, Without undue mechanical complications.

Further objects of the invention will appear from the following description in which the preferred embodiment of, the invention has been set forth in detail in conjunction with the ac- 20 companying drawing.

Referring to the drawing:

Fig. 1 is a side elevational view, partly in crosssection, illustrating a chair incorporating the present invention.

25 Fig. 2 is a cross-sectional View taken along the line 2-2 of Fig. 1.

The chair illustrated in the drawing consists generally of a seat structure 10, which may be of more or less conventional design. As illustrated the seat structure includes a metal frame carrying the cushions I l and I2, and the arm rests l3. Disposed beneath this seat structure there is a hydraulic operator designated generally by numeral M, but contrary to conventional construc- 35 tion this hydraulic operator is not directly connected to the seat structure. i

In order to guide the seat structure for movements in a vertical direction, two sets of telescopic members I6 and I! are provided. Mem- 40 hers is are in the form of tubes or pipes having their upper ends secured to the frame of the seat structure. Members I! are also in the form of tubes or pipes slidably engaged within the tubes l6, and having their lower ends rigidly secured to the base structure l8.

The hydraulic operator 14 consists of a stationary part I9, which can be in the form of a casting, and a hydraulic plunger 2| which is slidably fitted within the part IS. The control shaft 59 22 extends laterally as shown in Fig. 2 and is provided with an operating handle 23. One end of the shaft 22 is shown provided with a finger M, which engages the spring pressed plunger 25, as the handle 23 is swung in a counterclock- Hydraulic operators of this kind are well known by those skilled in the art, and need not be described in detail. By oscillating handle 23 a pump means is operated to introduce liquid under pressure into a cylinder, thereby raising the 5 plunger 2! by hydraulic pressure. By swinging the handle 23 to the limit of its movement in a counterclockwise direction as viewed in Fig. l, a liquid by-pass is opened permitting the liquid to flow out from the previously mentioned 19 cylinder, thereby permitting the plunger 2! to lower. In the past it has been quite customary, as previously pointed out, to mount the frame of the chair directly upon the upper end of the hydraulic plunger 2|.

In the present instance, motion multiplying means connects the plunger 2| with the seat structure, and this means makes use of a pair of flexible cables or chains 26. One end of each chain .is shown secured to a threaded screw 27, and this screw in turn extends through an opening in an anchoring tab 23. By means of a nut 29, which engages the screw 2'1, some latitude of adjustment is afforded. Each of the tabs or lugs 28 is carried by the corresponding tubu- 25 lar member lit. The other end of each chain 26 is anchored to the stationary casting IQ of the hydraulic operator, as indicated at 3!. Both of the chains 2% engage over sprocket wheels 32,

and these wheels in turn are suitably mounted 3o upon the hydraulic plunger 2i. Thus each sprocket wheel is journalled to a bracket 33, and each bracket in turn is secured to the hydraulic plunger 2|.

Operation of my chair can be briefly outlined as follows: The seat structure is supported by tension on the chains 26. When the hydraulic plunger 2| is raised or lowered a given amount by manipulation of the handle 23, such movement is imparted to the seat structure through the chains 26, and the amount of the movement imparted is double the movement of the plunger 2!. In other words if the hydraulic plunger 2! has an amplitude of movement of about four inches, the chair will have an amplitude of adjustm'ent of about eightinches. It will be evident that such an arrangement makes possible a chair which can be adjusted to a relatively low level for children or persons of short stature, and at the same time it can be adjusted over a relatively wide latitude. Although the hydraulic mechanism employed can be relatively compact and short as to over-all height, it is made capable of elevating the seat structure to a height such as might be attained by a substantially larger sized hydraulic structure directly connected to the seat structure. The mechanism employed is relatively simple, and there is little if any likelihood of mechanical failure.

I claim:

1. In a chair, a seat structure, a hydraulic operator unit underlying the seat structure, said operator unit including a fixed part and a plunger movable in a vertical direction, motion multiplying means connecting the plunger with said sea-t structure, said motion multiplying means including at least two flexible elements having their ends secured respectively to the seat structure and to the fixed part of the hydraulic operator, means movable by said plunger for operating said flexible elements, and two sets of vertically disposed guiding means, each set being disposed to one side of the operator unit and having no rigid connection to the movable part of said unit, said devices serving to guide the seat structure independently of the operator unit for movements of the seat structure in a vertical direction.

2. In a chair, a seat structure, guide means serving to support the seat structure for movements of the same in a vertical direction, said guide means including at least two sets of guide members with each set comprising slidably and telescopically engaged parts, a hydraulic operator unit disposed below the seat structure, said operator unit including a fixed part forming the base for the chair, and also including a hydraulic plunger movable hydraulically in a vertical direction, said two sets of guide members being disposed in spaced relationship on opposite sides of the hydraulic operator unit and. being secured to the fixed part of the hydraulic operator, a pair of sprockets carried by the hydraulic plunger, a pair of chains engaged over said sprockets, one end of each chain being effectively connected to the seat structure and the other end of each chain being anchored to the fixed part of the hydraulic operator, whereby when said plunger is moved hydraulically in a vertical direction, amplified movement in a vertical direction is imparted to the seat structure.

CLYDE L. HUNSICKER. 

